Conventional wheeled work machines include those provided with a traveling body in which an engine is mounted at the rear of a machine frame supported by front and rear wheels, and the traveling body is provided with a traveling system power transmission mechanism for transmitting power from the engine to the rear wheels, wherein a rotation table is supported on the traveling body so as to be able to swivel about a vertically oriented steering axis, a ground implement is provided to the front part of the rotation table, a driver seat is provided to the rear part, and a steering device for the traveling system and a steering device for the ground implement are provided to the rotation table (see Patent Document 1).
The traveling system power transmission mechanism has a rear wheel differential device, a hydrostatic transmission to which the power from the engine is transmitted, and a mechanical transmission device for transmitting power from the hydrostatic transmission to the rear wheel differential device.    [Patent Document 1] Japanese Laid-open Patent Application No. 2005-171608